Wireless devices are useful in communication systems for controlling and for one and two-way communications with other devices in the system. Examples of wireless devices include remote controls for garage door openers and televisions, cellular telephones, and wireless microphones. By virtue of being wireless, the wireless devices eliminate the need to be coupled through some type of a physical connection to the system, and thus are more portable. In many instances where these wireless devices are employed, each individual wireless device must be separately programmed in order to properly operate in a designated system, and requires re-programming in order to operate in a different system, or to operate with different other devices.
For example, a wireless remote for a garage door opener generally uses signals transmitted at some radio frequency. The signals typically includes a program code that must be set to match the code in the garage door opener system in order to allow the wireless remote to operate in the intended system. This program code is also used as a measure to prevent the controller from inadvertently opening another garage door, for example the neighbor's garage door, and to prevent unauthorized wireless controllers from being able to operate in the system in which the authorized wireless remote is operating. However, the wireless remote must be reprogrammed if the wireless remote is needed for operation in a different garage door system.
In another example wherein a wireless remote is employed as a television remote control, the wireless control needs to control the intended device (television or other electronic devices) without causing interference with a neighboring device (e.g., the television in the neighbor's house). Television remote controls generally operate using wavelengths in the infrared frequency range to transmit signals from the remote to the television, wherein the infrared frequencies are generally limited to a line-of-sight transmission path. Since a line-of-sight transmission path is obstructed by walls and other structural features usually associated with a home or building, the television remote is unlikely to interfere with another television or device that is not in a line-of-sight with the remote. This is generally true even when many of these remotes are operated in close proximity to one another but are separated by the structural obstructions, such as in an multi-unit apartment where remotes are operated in individual apartments without causing inference between apartments. One drawback of infrared signaling is that devices that use infrared signals have large power requirements as compared to devices that use radio frequency transmissions. However, because television remote controls generally only operate in a transmission mode for a fraction of the time the television is being used, a television remote does not require an excessively large battery, or frequent battery replacement or battery recharging.
Unlike television remotes, devices that use infrared transmissions and that have continual transmissions (e.g., a wireless microphone with high duty cycle or continuous periods of transmissions) have large power requirements compared to radio frequency devices. In order to meet the power requirements for an acceptable period of time (e.g., multiple hours of operation between battery replacements or recharging) the battery or batteries must be made larger, resulting in the wireless remote devices being bulky and heavy. In some remote devices, the use of an infrared frequency for such transmissions would limit operation times between battery recharge cycles to less than an full day, perhaps to only a few hours. In addition, a bulky and heavy remote device would be cumbersome for a user, such as a teacher, to hold and carry during a full work day, such as an entire school day. Further, a bulky and heavy remote device makes attaching the remote device to clothing of the user cumbersome, and in some instances even too cumbersome to be practical.
In wireless microphones, the use of radio frequency transmissions for a wireless microphone creates difficulties when two or more wireless microphones are used in close proximity to one another (e.g., in adjoining classrooms). In order to prevent interference between these microphones, each wireless microphone is often pre-programmed to a specific and separate frequency or channel to prevent interference with other wireless microphones operating in relatively close proximity, and to prevent interference between the systems associate with the separate wireless microphones. However, because each wireless microphone is pre-programmed to a specific frequency or channel, they cannot be moved to a different system, such as a local or adjacent room, without the need to re-program the moved wireless microphone to operate in the new system.
In addition, wireless microphones present a danger of inadvertent transmission. For example, if the user of the wireless microphone inadvertently forgets to turn off the microphone, unintended or even confidential conversation can reach the microphone and be broadcast to unintended listeners.
What is needed is one or more apparatus, systems, and methods to allow remote devices to automatically begin and to automatically terminate communications with one or more other devices as the remote devices are moved to and from the proximity of a given system, to prevent cross talk or other inadvertent interference between remotes devices, especially when these remotes are operating in a relatively close proximity to one another, and to minimize the chance of interference or inadvertently cross talk with other devices also transmitting signals in the area where the remote devices are being used Further, what is needed are remote devices that do not require re-programming when moved between systems, and that can automatically determine when a system is present on which communications can be established, and can automatically determine how to establish the communications in the newly detected system while minimizing or eliminating any interference between systems.